Fall 2014 Calendar of Events

Seminar-Thomas Baker University of Ottawa Wood Eye! Selective Aerobic Oxidation of C-C Bonds in Lignin Models using Base Metal Complexes: A Comparison of Oxovanadium and Copper Catalysts

Seminar-Thomas Baker University of Ottawa Wood Eye

September 12, 2014 3:00 PM  – 4:00 PM
Druckenmiller Hall, Room 020

Selective aerobic oxidation of lignin is being explored with a view to obtaining valuable aromatic chemicals.1 While many C-O bonds can be cleaved by heat or acid treatments to afford aromatic products such as vanillin, selective oxidative cleavage of C-C bonds may afford complementary aldehyde and acid products that could be converted subsequently into value-added aromatic chemicals. In previous work we showed that pyridine enables a novel 2 e- alcohol oxidation mechanism using oxovanadium complex catalysts and air.2 This led to different selectivity in C-C bond cleavage reactions of diols and a-hydroxyether lignin models vs. less basic solvents such as acetonitrile or DMSO.3 In contrast, use of simple copper halide salts in pyridine4 bypasses the C-H oxidation pathway in favour of direct C-C bond cleavage.5 Reactivity of the copper and vanadium catalysts in the oxidation of more complex b-O-4 lignin model compounds will be compared and the differences in selectivity discussed.

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Seminar- Paul Cheong Oregon State University. Strategic Applications of Chemical Theory and Computations to Organic Synthesis and Material Science

Seminar- Paul Cheong Oregon State University

September 18, 2014 2:00 PM  – 5:00 PM
Druckenmiller Hall, Cleaveland 151

Professor Paul Cheong is a former Bowdoin graduate whose experiences at Bowdoin were pivotal in the selection of topics and methods in his research career. The Cheong group applies and develops state-of-the-art computational tools to discover and explain fundamental and practical principles that underlie organic synthesis and material science. In this seminar, the latest discoveries in the mechanism and origins of stereoselectivity in peptide-catalyzed reactions will be disclosed. In addition, recent foray into inorganic material science will be discussed. Specifically, a rapid method to predict aqueous metal cluster stabilities & electronic properties and a computational method to predict the structure and electronic properties of amorphous materials will be disclosed."

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Stem Cell Tumors: Getting Their Fix on the Fly

Stem Cell Tumors

September 18, 2014 4:00 PM  – 5:00 PM
Druckenmiller Hall, Room 016

Michelle Markstein, Assistant Professor, Biology Department, University of Massachusetts, Amherst

Research Interests: Stem cells and cancer

The Markstein lab seeks to understand the stem cell properties of cancer cells with the goal of developing new cancer therapeutics. We focus on cell-cell interactions within the stem cell microenvironment and on the plasticity of stem cell genome architecture. Our approach is in vivo, using the fruit fly Drosophila melanogaster to screen for anti-cancer drugs and drug targets.

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Seminar- Donald Elmore- Wellesley College.Design and Characterization of Histone-Derived Antimicrobial Peptides

Donald Elmore Wellesley College

September 26, 2014 3:00 PM  – 4:00 PM
Druckenmiller Hall, Room 020

Bacteria that have developed antibiotic resistance pose an increasingly large health risk to the population. Antimicrobial peptides are small proteins produced by a wide variety of organisms. These peptides represent a potential alternative to conventional antibiotics in the fight against resistant bacterial. Although the antimicrobial activity of full histones and histone fragments has been known for decades, relatively little research has investigated their mechanism of action. Buforin II, the best characterized histone-derived antimicrobial peptide (HDAP), is thought to target bacteria by translocating across the cell membrane and interacting with intracellular nucleic acids. My lab utilizes a broad range of methods, such as spectroscopic measurements, cellular assays, and computational modeling, to determine whether other HDAPs utilize a similar mechanism. In turn, understanding the structure-function relationships of these naturally occurring HDAPs has allowed us to begin the design of novel antimicrobial peptides based on histone structures. This talk will describe our recent characterization and design efforts that have given us increased insight into this intriguing family of therapeutic agents

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Seminar- Bill Wuest-Temple University. Draining the Moat: A Natural Product-Inspired Approach to Combat Biofilms

Bill Wuest Temple University

October 3, 2014 3:00 PM  – 4:00 PM
Druckenmiller Hall, Room 020

The importance of natural products as anticancer and antibiotic compounds is undisputed due to their wide application as potent and effective pharmaceuticals. In contrast, the investigation of natural products toward biofilm-implicated bacterial infections, a rising concern among scientists and medical professionals, has been significantly understudied. Biofilm formation is the first line of defense for many bacteria similarly to how a moat protects a castle, and it is this defense that makes them so hard to combat. Over the past three years our group has looked to Nature for inspiring chemical scaffolds and have identified promising candidates that perturb bacterial biofilms. Two ongoing projects, which focus on cyclic diguanylate monophosphate (c-di-GMP) and norspermidine, will be discussed in detail.   C-di-GMP is an important nucleotide signaling molecule in many pathogenic bacteria. Our group has initiated a bioorganic venture toward the synthesis and biological evaluation of a library of rationally designed analogs with the dual purpose to act both as biofilm inhibitors and chemical probes. Specifically, our work focuses on the construction of non-hydrolyzable, cell-permeable analogs with discrete conformations that incorporate charge neutral phosphate bioisosteres to replace the natural phosphate linkages. In contrast to the chemical complexity of c-di-GMP, norspermidine represents a simpler starting point for synthetic investigation. Earlier reports indicated that the polyamine possessed interesting antibiofilm activity and our group sought to expand these findings to a class of quaternary ammonium cationic (QAC) analogs constructed in collaboration with the Minbiole Group at Villanova University. Over the past year we have synthesized and evaluated over sixty synthetic analogs and identified some of the most potent biofilm-eradicating compounds to date. The talk will highlight the conceptualization of the research hypotheses of both projects, the synthesis and evaluation of each class of analogs, and the current progress toward the construction of c-di-GMP analogs and solid-supported QAC antibiofilm surfaces.

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Dharni Vasudevan presents: "Contaminants in the Environment: Factors Influencing Chemical Fate, Effects, and Policies"

Dharni Vasudevan

November 4, 2014 12:00 PM  – 1:00 PM
Moulton Union, Main Lounge


Dharni Vasudevan
, Professor of Chemistry and Environmental Studies is the featured speaker.  The title of her talk is: "Contaminants in the Environment: Factors Influencing Chemical Fate, Effects, and Policies."

Open to faculty and staff.
Buffet lunch $3, or bring your own lunch.

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